Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level ad and internet tracker blocking application. From 6.0 to before 6.5, client hostnames and IP addresses from the FTL database are rendered into the DOM without escaping in network.js (Network page) and charts.js/index.js (Dashboard chart tooltips). While upstream validation in dnsmasq and FTL blocks HTML characters via normal DHCP/DNS paths, the web UI performs no output escaping — an inconsistency with other fields in the same file that are properly escaped. This vulnerability is fixed in 6.5.